Bocomo, I would define "working" as creating a healthier pond. That stated, I don't know what metrics are used to judge a healthy pond. I know I have an algae issue on the south end, but in the middle, things look pretty good. Is it healthy...no idea. Curious to get everyone's thoughts on pond testing as well. Our chemical applicator will charge $200 to do it, but I'm hoping that is something DIY if it's helpful.